Kubernetes for Beginners: Deploy, Scale & Manage Containers in 2026

Learn Kubernetes from scratch — pods, deployments, services, ingress, ConfigMaps, and scaling. A practical guide with real examples to get your first app running on K8s.

16 अप्रैल 20267 min read

What Is Kubernetes?

Kubernetes (K8s) is a container orchestration platform. If Docker is how you package your app, Kubernetes is how you run it in production — handling deployment, scaling, networking, and self-healing automatically.

The problem Kubernetes solves:

You have 50 containers across 10 servers — who decides which container runs where?
A container crashes at 3 AM — who restarts it?
Traffic spikes 10x — who spins up more instances?
You deploy a bad version — who rolls it back?

Kubernetes handles all of this.

Without K8s:  You manually manage containers on servers
With K8s:     You describe what you want, K8s makes it happen

Core Concepts

The Hierarchy

Cluster
  └── Nodes (physical/virtual machines)
        └── Pods (smallest deployable unit)
              └── Containers (your app)

Key Resources

| Resource | What It Does | |----------|-------------| | Pod | Runs one or more containers together | | Deployment | Manages pods — scaling, updates, rollbacks | | Service | Stable network endpoint for pods | | Ingress | Routes external HTTP traffic to services | | ConfigMap | Stores configuration (env vars, files) | | Secret | Stores sensitive data (passwords, tokens) | | Namespace | Virtual cluster for isolation |

Setting Up

Local Development

bash

# Option 1: minikube (most popular)
# Install minikube
curl -LO https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64
sudo install minikube-linux-amd64 /usr/local/bin/minikube

# Start cluster
minikube start

# Option 2: kind (Kubernetes in Docker)
go install sigs.k8s.io/kind@latest
kind create cluster

# Option 3: Docker Desktop (Mac/Windows)
# Enable Kubernetes in Docker Desktop settings

Install kubectl

bash

# Linux
curl -LO "https://dl.k8s.io/release/$(curl -sL https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"
sudo install kubectl /usr/local/bin/kubectl

# Verify
kubectl version --client
kubectl cluster-info

Your First Deployment

Step 1: Create a Deployment

yaml

# app-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-app
  labels:
    app: my-app
spec:
  replicas: 3                    # Run 3 copies
  selector:
    matchLabels:
      app: my-app
  template:
    metadata:
      labels:
        app: my-app
    spec:
      containers:
        - name: my-app
          image: nginx:alpine     # Your container image
          ports:
            - containerPort: 80
          resources:
            requests:
              memory: "64Mi"
              cpu: "50m"
            limits:
              memory: "128Mi"
              cpu: "100m"

bash

# Apply it
kubectl apply -f app-deployment.yaml

# Check status
kubectl get deployments
kubectl get pods

Output:

NAME     READY   UP-TO-DATE   AVAILABLE   AGE
my-app   3/3     3            3           30s

NAME                      READY   STATUS    RESTARTS   AGE
my-app-6d8f7b4d5-abc12   1/1     Running   0          30s
my-app-6d8f7b4d5-def34   1/1     Running   0          30s
my-app-6d8f7b4d5-ghi56   1/1     Running   0          30s

Step 2: Expose with a Service

yaml

# app-service.yaml
apiVersion: v1
kind: Service
metadata:
  name: my-app-service
spec:
  selector:
    app: my-app                   # Matches pods with this label
  ports:
    - protocol: TCP
      port: 80                    # Service port
      targetPort: 80              # Container port
  type: ClusterIP                 # Internal only (default)

bash

kubectl apply -f app-service.yaml
kubectl get services

Step 3: Expose Externally

yaml

# For local development / cloud providers with load balancers
apiVersion: v1
kind: Service
metadata:
  name: my-app-lb
spec:
  selector:
    app: my-app
  ports:
    - port: 80
      targetPort: 80
  type: LoadBalancer              # External access

bash

# For minikube
minikube service my-app-lb

Scaling

Manual Scaling

bash

# Scale to 5 replicas
kubectl scale deployment my-app --replicas=5

# Scale down to 2
kubectl scale deployment my-app --replicas=2

# Check
kubectl get pods -w   # Watch mode

Auto-Scaling (HPA)

yaml

# hpa.yaml
apiVersion: autoscaling/v2
kind: HorizontalPodAutoscaler
metadata:
  name: my-app-hpa
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: my-app
  minReplicas: 2
  maxReplicas: 10
  metrics:
    - type: Resource
      resource:
        name: cpu
        target:
          type: Utilization
          averageUtilization: 70    # Scale up when CPU > 70%

bash

kubectl apply -f hpa.yaml
kubectl get hpa

Configuration

ConfigMaps (Non-Sensitive Data)

yaml

# configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: app-config
data:
  DATABASE_HOST: "postgres.default.svc.cluster.local"
  LOG_LEVEL: "info"
  MAX_CONNECTIONS: "100"

Secrets (Sensitive Data)

bash

# Create from command line
kubectl create secret generic app-secrets \
  --from-literal=DB_PASSWORD=supersecret \
  --from-literal=API_KEY=abc123

Using Config in Pods

yaml

spec:
  containers:
    - name: my-app
      image: my-app:latest
      envFrom:
        - configMapRef:
            name: app-config       # All keys become env vars
        - secretRef:
            name: app-secrets
      env:
        - name: SPECIAL_VAR       # Single value from ConfigMap
          valueFrom:
            configMapKeyRef:
              name: app-config
              key: LOG_LEVEL

Ingress (HTTP Routing)

Ingress routes external HTTP/HTTPS traffic to services based on hostname or path.

yaml

# ingress.yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: app-ingress
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
spec:
  ingressClassName: nginx
  rules:
    - host: myapp.example.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: frontend-service
                port:
                  number: 80
          - path: /api
            pathType: Prefix
            backend:
              service:
                name: backend-service
                port:
                  number: 8080
  tls:
    - hosts:
        - myapp.example.com
      secretName: tls-secret

bash

# Install ingress controller (minikube)
minikube addons enable ingress

# Apply
kubectl apply -f ingress.yaml

Rolling Updates and Rollbacks

Update Image

bash

# Update to new version
kubectl set image deployment/my-app my-app=my-app:v2

# Watch the rollout
kubectl rollout status deployment/my-app

Output:

Waiting for deployment "my-app" rollout to finish: 1 out of 3 new replicas have been updated...
Waiting for deployment "my-app" rollout to finish: 2 out of 3 new replicas have been updated...
deployment "my-app" successfully rolled out

Rollback

bash

# View history
kubectl rollout history deployment/my-app

# Rollback to previous version
kubectl rollout undo deployment/my-app

# Rollback to specific revision
kubectl rollout undo deployment/my-app --to-revision=2

Rolling Update Strategy

yaml

spec:
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 1            # Max pods above desired count during update
      maxUnavailable: 0      # Zero downtime — always keep all pods running

Debugging

Essential Commands

bash

# Pod status
kubectl get pods -o wide

# Detailed pod info
kubectl describe pod my-app-6d8f7b4d5-abc12

# Container logs
kubectl logs my-app-6d8f7b4d5-abc12
kubectl logs -f my-app-6d8f7b4d5-abc12    # Follow/stream

# Execute command in pod
kubectl exec -it my-app-6d8f7b4d5-abc12 -- /bin/sh

# Port forward (access pod directly)
kubectl port-forward my-app-6d8f7b4d5-abc12 8080:80

# Get all resources in namespace
kubectl get all -n default

# Delete stuck pods
kubectl delete pod my-app-6d8f7b4d5-abc12 --grace-period=0 --force

Common Issues

| Symptom | Check | Fix | |---------|-------|-----| | CrashLoopBackOff | kubectl logs <pod> | Fix app crash, check env vars | | ImagePullBackOff | kubectl describe pod | Fix image name, check registry auth | | Pending | kubectl describe pod | Check resources, node capacity | | 0/1 Running | Readiness probe | Fix health check endpoint |

Health Checks

yaml

spec:
  containers:
    - name: my-app
      image: my-app:latest
      livenessProbe:              # Is the container alive?
        httpGet:
          path: /healthz
          port: 8080
        initialDelaySeconds: 10
        periodSeconds: 10
      readinessProbe:             # Is the container ready for traffic?
        httpGet:
          path: /ready
          port: 8080
        initialDelaySeconds: 5
        periodSeconds: 5
      startupProbe:               # Has the container started?
        httpGet:
          path: /healthz
          port: 8080
        failureThreshold: 30
        periodSeconds: 10

Namespaces

bash

# Create namespace
kubectl create namespace staging

# Deploy to namespace
kubectl apply -f deployment.yaml -n staging

# List pods in namespace
kubectl get pods -n staging

# Set default namespace
kubectl config set-context --current --namespace=staging

Quick Reference: kubectl Commands

bash

# CRUD
kubectl get <resource>                    # List
kubectl describe <resource> <name>        # Details
kubectl apply -f <file>                   # Create/update
kubectl delete -f <file>                  # Delete

# Shortcuts
kubectl get po           # pods
kubectl get deploy       # deployments
kubectl get svc          # services
kubectl get ing          # ingress
kubectl get ns           # namespaces
kubectl get no           # nodes

# Output formats
kubectl get pods -o wide                  # Extra columns
kubectl get pods -o yaml                  # Full YAML
kubectl get pods -o json                  # Full JSON
kubectl get pods --sort-by=.status.startTime

# Labels
kubectl get pods -l app=my-app            # Filter by label
kubectl label pod my-pod env=production   # Add label

What's Next?

Once you're comfortable with the basics:

Helm — Package manager for Kubernetes (charts = reusable templates)
Kustomize — Customize YAML without templates
ArgoCD — GitOps continuous deployment
Prometheus + Grafana — Monitoring and dashboards
Istio / Linkerd — Service mesh for advanced networking
Cert-Manager — Automatic TLS certificates

The key insight: Kubernetes is declarative. You tell it what you want (3 replicas, 80% CPU limit, rolling updates), and it figures out how to make it happen. Start simple, add complexity only when you need it.

DevOps Kubernetes Cloud

Kubernetes for Beginners: Deploy, Scale & Manage Containers in 2026

Learn Kubernetes from scratch — pods, deployments, services, ingress, ConfigMaps, and scaling. A practical guide with real examples to get your first app running on K8s.

16 अप्रैल 20267 min read

What Is Kubernetes?

The problem Kubernetes solves:

You have 50 containers across 10 servers — who decides which container runs where?
A container crashes at 3 AM — who restarts it?
Traffic spikes 10x — who spins up more instances?
You deploy a bad version — who rolls it back?

Kubernetes handles all of this.

Without K8s:  You manually manage containers on servers
With K8s:     You describe what you want, K8s makes it happen

Core Concepts

The Hierarchy

Cluster
  └── Nodes (physical/virtual machines)
        └── Pods (smallest deployable unit)
              └── Containers (your app)

Key Resources

Setting Up

Local Development

bash

# Option 1: minikube (most popular)
# Install minikube
curl -LO https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64
sudo install minikube-linux-amd64 /usr/local/bin/minikube

# Start cluster
minikube start

# Option 2: kind (Kubernetes in Docker)
go install sigs.k8s.io/kind@latest
kind create cluster

# Option 3: Docker Desktop (Mac/Windows)
# Enable Kubernetes in Docker Desktop settings

Install kubectl

bash

# Linux
curl -LO "https://dl.k8s.io/release/$(curl -sL https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"
sudo install kubectl /usr/local/bin/kubectl

# Verify
kubectl version --client
kubectl cluster-info

Your First Deployment

Step 1: Create a Deployment

yaml

# app-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-app
  labels:
    app: my-app
spec:
  replicas: 3                    # Run 3 copies
  selector:
    matchLabels:
      app: my-app
  template:
    metadata:
      labels:
        app: my-app
    spec:
      containers:
        - name: my-app
          image: nginx:alpine     # Your container image
          ports:
            - containerPort: 80
          resources:
            requests:
              memory: "64Mi"
              cpu: "50m"
            limits:
              memory: "128Mi"
              cpu: "100m"

bash

# Apply it
kubectl apply -f app-deployment.yaml

# Check status
kubectl get deployments
kubectl get pods

Output:

NAME     READY   UP-TO-DATE   AVAILABLE   AGE
my-app   3/3     3            3           30s

NAME                      READY   STATUS    RESTARTS   AGE
my-app-6d8f7b4d5-abc12   1/1     Running   0          30s
my-app-6d8f7b4d5-def34   1/1     Running   0          30s
my-app-6d8f7b4d5-ghi56   1/1     Running   0          30s

Step 2: Expose with a Service

yaml

# app-service.yaml
apiVersion: v1
kind: Service
metadata:
  name: my-app-service
spec:
  selector:
    app: my-app                   # Matches pods with this label
  ports:
    - protocol: TCP
      port: 80                    # Service port
      targetPort: 80              # Container port
  type: ClusterIP                 # Internal only (default)

bash

kubectl apply -f app-service.yaml
kubectl get services

Step 3: Expose Externally

yaml

# For local development / cloud providers with load balancers
apiVersion: v1
kind: Service
metadata:
  name: my-app-lb
spec:
  selector:
    app: my-app
  ports:
    - port: 80
      targetPort: 80
  type: LoadBalancer              # External access

bash

# For minikube
minikube service my-app-lb

Scaling

Manual Scaling

bash

# Scale to 5 replicas
kubectl scale deployment my-app --replicas=5

# Scale down to 2
kubectl scale deployment my-app --replicas=2

# Check
kubectl get pods -w   # Watch mode

Auto-Scaling (HPA)

yaml

# hpa.yaml
apiVersion: autoscaling/v2
kind: HorizontalPodAutoscaler
metadata:
  name: my-app-hpa
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: my-app
  minReplicas: 2
  maxReplicas: 10
  metrics:
    - type: Resource
      resource:
        name: cpu
        target:
          type: Utilization
          averageUtilization: 70    # Scale up when CPU > 70%

bash

kubectl apply -f hpa.yaml
kubectl get hpa

Configuration

ConfigMaps (Non-Sensitive Data)

yaml

# configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: app-config
data:
  DATABASE_HOST: "postgres.default.svc.cluster.local"
  LOG_LEVEL: "info"
  MAX_CONNECTIONS: "100"

Secrets (Sensitive Data)

bash

# Create from command line
kubectl create secret generic app-secrets \
  --from-literal=DB_PASSWORD=supersecret \
  --from-literal=API_KEY=abc123

Using Config in Pods

yaml

spec:
  containers:
    - name: my-app
      image: my-app:latest
      envFrom:
        - configMapRef:
            name: app-config       # All keys become env vars
        - secretRef:
            name: app-secrets
      env:
        - name: SPECIAL_VAR       # Single value from ConfigMap
          valueFrom:
            configMapKeyRef:
              name: app-config
              key: LOG_LEVEL

Ingress (HTTP Routing)

Ingress routes external HTTP/HTTPS traffic to services based on hostname or path.

yaml

# ingress.yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: app-ingress
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
spec:
  ingressClassName: nginx
  rules:
    - host: myapp.example.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: frontend-service
                port:
                  number: 80
          - path: /api
            pathType: Prefix
            backend:
              service:
                name: backend-service
                port:
                  number: 8080
  tls:
    - hosts:
        - myapp.example.com
      secretName: tls-secret

bash

# Install ingress controller (minikube)
minikube addons enable ingress

# Apply
kubectl apply -f ingress.yaml

Rolling Updates and Rollbacks

Update Image

bash

# Update to new version
kubectl set image deployment/my-app my-app=my-app:v2

# Watch the rollout
kubectl rollout status deployment/my-app

Output:

Waiting for deployment "my-app" rollout to finish: 1 out of 3 new replicas have been updated...
Waiting for deployment "my-app" rollout to finish: 2 out of 3 new replicas have been updated...
deployment "my-app" successfully rolled out

Rollback

bash

# View history
kubectl rollout history deployment/my-app

# Rollback to previous version
kubectl rollout undo deployment/my-app

# Rollback to specific revision
kubectl rollout undo deployment/my-app --to-revision=2

Rolling Update Strategy

yaml

spec:
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 1            # Max pods above desired count during update
      maxUnavailable: 0      # Zero downtime — always keep all pods running

Debugging

Essential Commands

bash

# Pod status
kubectl get pods -o wide

# Detailed pod info
kubectl describe pod my-app-6d8f7b4d5-abc12

# Container logs
kubectl logs my-app-6d8f7b4d5-abc12
kubectl logs -f my-app-6d8f7b4d5-abc12    # Follow/stream

# Execute command in pod
kubectl exec -it my-app-6d8f7b4d5-abc12 -- /bin/sh

# Port forward (access pod directly)
kubectl port-forward my-app-6d8f7b4d5-abc12 8080:80

# Get all resources in namespace
kubectl get all -n default

# Delete stuck pods
kubectl delete pod my-app-6d8f7b4d5-abc12 --grace-period=0 --force

Common Issues

Health Checks

yaml

spec:
  containers:
    - name: my-app
      image: my-app:latest
      livenessProbe:              # Is the container alive?
        httpGet:
          path: /healthz
          port: 8080
        initialDelaySeconds: 10
        periodSeconds: 10
      readinessProbe:             # Is the container ready for traffic?
        httpGet:
          path: /ready
          port: 8080
        initialDelaySeconds: 5
        periodSeconds: 5
      startupProbe:               # Has the container started?
        httpGet:
          path: /healthz
          port: 8080
        failureThreshold: 30
        periodSeconds: 10

Namespaces

bash

# Create namespace
kubectl create namespace staging

# Deploy to namespace
kubectl apply -f deployment.yaml -n staging

# List pods in namespace
kubectl get pods -n staging

# Set default namespace
kubectl config set-context --current --namespace=staging

Quick Reference: kubectl Commands

bash

# CRUD
kubectl get <resource>                    # List
kubectl describe <resource> <name>        # Details
kubectl apply -f <file>                   # Create/update
kubectl delete -f <file>                  # Delete

# Shortcuts
kubectl get po           # pods
kubectl get deploy       # deployments
kubectl get svc          # services
kubectl get ing          # ingress
kubectl get ns           # namespaces
kubectl get no           # nodes

# Output formats
kubectl get pods -o wide                  # Extra columns
kubectl get pods -o yaml                  # Full YAML
kubectl get pods -o json                  # Full JSON
kubectl get pods --sort-by=.status.startTime

# Labels
kubectl get pods -l app=my-app            # Filter by label
kubectl label pod my-pod env=production   # Add label

What's Next?

Once you're comfortable with the basics:

Helm — Package manager for Kubernetes (charts = reusable templates)
Kustomize — Customize YAML without templates
ArgoCD — GitOps continuous deployment
Prometheus + Grafana — Monitoring and dashboards
Istio / Linkerd — Service mesh for advanced networking
Cert-Manager — Automatic TLS certificates

What Is Kubernetes?

Core Concepts

The Hierarchy

Key Resources

Setting Up

Local Development

Install kubectl

Your First Deployment

Step 1: Create a Deployment

Step 2: Expose with a Service

Step 3: Expose Externally

Scaling

Manual Scaling

Auto-Scaling (HPA)

Configuration

ConfigMaps (Non-Sensitive Data)

Secrets (Sensitive Data)

Using Config in Pods

Ingress (HTTP Routing)

Rolling Updates and Rollbacks

Update Image

Rollback

Rolling Update Strategy

Debugging

Essential Commands

Common Issues

Health Checks

Namespaces

Quick Reference: kubectl Commands

What's Next?

संबंधित लेख

Advanced Git: Rebase, Cherry-Pick, Bisect & Reflog Explained

Docker for Beginners: Install, Run & Deploy Your First Container

How to Set Up a Reverse Proxy with Nginx for Self-Hosted Apps

क्या यह लेख उपयोगी था?

अपडेट रहें

What Is Kubernetes?

Core Concepts

The Hierarchy

Key Resources

Setting Up

Local Development

Install kubectl

Your First Deployment

Step 1: Create a Deployment

Step 2: Expose with a Service

Step 3: Expose Externally

Scaling

Manual Scaling

Auto-Scaling (HPA)

Configuration

ConfigMaps (Non-Sensitive Data)

Secrets (Sensitive Data)

Using Config in Pods

Ingress (HTTP Routing)

Rolling Updates and Rollbacks

Update Image

Rollback

Rolling Update Strategy

Debugging

Essential Commands

Common Issues

Health Checks

Namespaces

Quick Reference: kubectl Commands

What's Next?

संबंधित लेख

Advanced Git: Rebase, Cherry-Pick, Bisect & Reflog Explained

Docker for Beginners: Install, Run & Deploy Your First Container

How to Set Up a Reverse Proxy with Nginx for Self-Hosted Apps

क्या यह लेख उपयोगी था?

अपडेट रहें